mpsafe interrupts for mfi(4)

[David Gwynne]

...and some mpsafety in the scsi_cmd path.

this is working well for me, but considering how used it is i would
appreciate some extra tests.

ok?

Index: pci/mfi_pci.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/mfi_pci.c,v
retrieving revision 1.28
diff -u -p -r1.28 mfi_pci.c
--- pci/mfi_pci.c       14 Aug 2012 04:10:14 -0000      1.28
+++ pci/mfi_pci.c       8 Sep 2014 04:47:03 -0000
@@ -133,8 +133,8 @@ mfi_pci_attach(struct device *parent, st
        }
        printf(": %s\n", pci_intr_string(pa->pa_pc, ih));
 
-       sc->sc_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO, mfi_intr, sc,
-           sc->sc_dev.dv_xname);
+       sc->sc_ih = pci_intr_establish(pa->pa_pc, ih, IPL_BIO | IPL_MPSAFE,
+           mfi_intr, sc, sc->sc_dev.dv_xname);
        if (!sc->sc_ih) {
                printf("%s: can't establish interrupt\n", DEVNAME(sc));
                goto unmap;
Index: ic/mfi.c
===================================================================
RCS file: /cvs/src/sys/dev/ic/mfi.c,v
retrieving revision 1.155
diff -u -p -r1.155 mfi.c
--- ic/mfi.c    15 Aug 2014 02:27:02 -0000      1.155
+++ ic/mfi.c    8 Sep 2014 04:47:03 -0000
@@ -199,6 +199,8 @@ mfi_get_ccb(void *cookie)
        struct mfi_softc        *sc = cookie;
        struct mfi_ccb          *ccb;
 
+       KERNEL_UNLOCK();
+
        mtx_enter(&sc->sc_ccb_mtx);
        ccb = SLIST_FIRST(&sc->sc_ccb_freeq);
        if (ccb != NULL) {
@@ -208,6 +210,7 @@ mfi_get_ccb(void *cookie)
        mtx_leave(&sc->sc_ccb_mtx);
 
        DNPRINTF(MFI_D_CCB, "%s: mfi_get_ccb: %p\n", DEVNAME(sc), ccb);
+       KERNEL_LOCK();
 
        return (ccb);
 }
@@ -220,9 +223,11 @@ mfi_put_ccb(void *cookie, void *io)
 
        DNPRINTF(MFI_D_CCB, "%s: mfi_put_ccb: %p\n", DEVNAME(sc), ccb);
 
+       KERNEL_UNLOCK();
        mtx_enter(&sc->sc_ccb_mtx);
        SLIST_INSERT_HEAD(&sc->sc_ccb_freeq, ccb, ccb_link);
        mtx_leave(&sc->sc_ccb_mtx);
+       KERNEL_LOCK();
 }
 
 void
@@ -1108,7 +1113,9 @@ mfi_scsi_xs_done(struct mfi_softc *sc, s
                break;
        }
 
+       KERNEL_LOCK();
        scsi_done(xs);
+       KERNEL_UNLOCK();
 }
 
 int
@@ -1174,6 +1181,8 @@ mfi_scsi_cmd(struct scsi_xfer *xs)
        DNPRINTF(MFI_D_CMD, "%s: mfi_scsi_cmd opcode: %#x\n",
            DEVNAME(sc), xs->cmd->opcode);
 
+       KERNEL_UNLOCK();
+
        if (!sc->sc_ld[target].ld_present) {
                DNPRINTF(MFI_D_CMD, "%s: invalid target %d\n",
                    DEVNAME(sc), target);
@@ -1236,11 +1245,13 @@ mfi_scsi_cmd(struct scsi_xfer *xs)
        else 
                mfi_start(sc, ccb);
 
+       KERNEL_LOCK();
        return;
 
 stuffup:
        xs->error = XS_DRIVER_STUFFUP;
 complete:
+       KERNEL_LOCK();
        scsi_done(xs);
 }
 
@@ -2492,6 +2503,8 @@ mfi_pd_scsi_cmd(struct scsi_xfer *xs)
        struct mfi_pass_frame *pf = &ccb->ccb_frame->mfr_pass;
        struct mfi_pd_link *pl = sc->sc_pd->pd_links[link->target];
 
+       KERNEL_UNLOCK();
+
        mfi_scrub_ccb(ccb);
        xs->error = XS_NOERROR;
 
@@ -2532,9 +2545,11 @@ mfi_pd_scsi_cmd(struct scsi_xfer *xs)
        else
                mfi_start(sc, ccb);
 
+       KERNEL_LOCK();
        return;
 
 stuffup:
        xs->error = XS_DRIVER_STUFFUP;
+       KERNEL_LOCK();
        scsi_done(xs);
 }